DESCRIPTION (Investigator's abstract): The long range objective of this project is to identify the gene responsible for a specific human retinal degeneration, the X-linked cone-rod dystrophy (COD-1) and eventually understand its function in the retina. We began linkage studies on COD-1 over nine years ago and we have refined the COD-1 locus to a limited region of Xp11.4. We have access to at least 13 COD-1 families which we will use to further localize and test for the causative gene using a combination of positional and candidate gene screening methodologies. We will identify and characterize the candidate genes using genomic informatics and by direct characterization of COD-I critical region, as defined by linkage mapping and haplotype analyses. We will perform mutation screening of candidate genes using DNA from affected COD-I individuals. This study will help to resolve issues of allelic and genetic heterogeneity for X-linked retinal degenerations and will further our understanding of the biology of degenerative eye diseases.